Ink-jet inks typically comprise an ink vehicle and a colorant, the latter of which may be a dye or a pigment. Dye-based ink-jet inks used in photographic image printing are almost always water-soluble dyes. As a result, such dye-based ink-jet inks are usually not very water fast, i.e. images tend to shift in hue and edge sharpness is reduced upon exposure to humid conditions, especially when printed on media substrates having a porous ink-receiving layer. In addition, images created from these water-soluble dye-based ink-jet inks tend to fade over time, such as when exposed to ambient light and/or air. Pigment-based inks on the other hand, allow the creation of images that are vastly improved in humid fastness and image fade resistance. Pigment based images, however, are inferior to dye-based ink-jet inks with respect to the desirable trait of color saturation and gloss uniformity.
Print media surfaces play a key role in fade properties, humid fastness, and the quality of ink-jet produced printed images. Thus, for a given ink, the degree of air fade, humid fastness, and image quality can be dependent on the chemistry of the media surface. As a result, many ink-jet inks can be made to perform better when an appropriate media surface is used. For example, pigment based ink can be very sensitive to media coating compositions. Images printed with pigment based ink on porous media usually exhibit haze, lower gloss, or even completely lose gloss (also referred to as degloss) at high ink density. There are also problems of air fade and humid fastness associated with dye-based ink-jet inks as well. The ability for a printed image to be handled and exhibit scratch resistance can also be poor if the media is not compatible with ink-jet inks, particularly pigment-based ink-jet inks.
As such, it would be an advancement in the art to provide images that exhibit high gloss and high gloss uniformity with both dye and pigment based ink. Without this degloss phenomena, the gloss uniformity can be significantly improved in appearance. Also because of tight packing of pigment colorants in pigment-based ink-jet inks, the scratch resistance of the printed image can be enhanced. Still further, color gamut, black density, and humid fastness for dye-based ink-jet inks can also be significantly improved.